Question

Which reference to comets, consider the following statements?
1. They revolve around the Sun along a circular orbit.
2. The tail of the comet always points towards the Sun during its revolution due to Sun's gravitational force.
3. Halley's comet completes one revolution around the Sun in 76 years.
4. The next appearance of Halley's comet near the Earth will be in the year 2061.
Which of the statement(s) is/are correct?
A) 1 only
B) 2 and 3 only
C) 3 and 4 only
D) 1,2,3 and 4

Answer 1

Hint: A comet is a tiny, frozen entity in the Solar System that warms up and begins to leak gases as it approaches the Sun, a process known as outgassing. This results in a visible atmosphere or coma, as well as a tail in rare cases. The impact of solar radiation and the solar wind on the nucleus of the comet cause these behaviours.

Complete answer:
The presence of an extensive, gravitationally unbound atmosphere surrounding the core nucleus distinguishes comets from asteroids. The coma, the centre region immediately around the nucleus, and the tail, a generally linear piece composed of dust or gas pushed out of the coma by the Sun's light pressure or out streaming solar wind plasma, are two distinct parts of this atmosphere.

A comet's orbit is usually an elongated thin ellipse and does not follow a circular path. The tail of a comet is drawn away from the Sun by the presence of solar wind, which separates the comet's tail from its head. Halley's comet does make one circuit around the Sun every 76 years, and its most recent visit to the Earth was in 1985. As a result, the next time it visits will be in 2061.

So, the answer is Option C i.e, 3 and 4 only

Note: There are 4595 known comets as of April 2021, a number that is continually increasing as more are discovered. However, because the reservoir of comet-like bodies in the outer Solar System is projected to be one trillion, this represents only a small proportion of the total possible comet population. Every year, about one comet is visible to the human eye, though many of them are dim and uninteresting.